FIG. 11 shows a conventional voltage converter circuit. In FIG. 11, voltage converter IC 143, capacitor 141 and capacitor 142 are placed on a layer, namely, they are placed in two dimensions. Voltage converter IC 143 converts a voltage, and each one of capacitors 141, 142 has a capacity of not less than 1 μF and are coupled between IC 143 and the grounding, thereby removing noises.
Since capacitors 141 and 142 have a capacity of not less than 1 μF, they are large in dimensions, so that the layout of IC 143, capacitor 141 and capacitor 142 is restricted when they are mounted in the two dimensions. Therefore, this place problem limits those capacitors to make full use of their noise-removing ability, which should have been effective if they had been placed immediately close to the voltage converter IC.
A height of those capacitors, which are chip components, determines a height of the entire circuit, and a total cross sectional area in a horizontal direction of the voltage-converter IC and the capacitors determines an area occupied by the entire circuit.